The film is the dramatised story of Thor Heyerdahl and his Kon-Tiki expedition of 1947. While the prevailing theories of the time held that Polynesia had been settled by peoples migrating from the west, Heyerdahl, an experimental ethnographer and adventurer, sets out to prove his theory that people from South America settled the islands in pre-Columbian times. During the three months aboard the primitive vessel named after Inca god of Sun and storm, Kon-Tiki, the crew`s scientific reenactment of the legendary voyage from the coast of Peru to the Polynesian islands is met with setbacks in the form of storms, sharks, and other perils of the open sea.